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Thread: Tell me about maneuvering speed - Va

  1. #1
    L18C-95's Avatar
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    Tell me about maneuvering speed - Va

    I found this old article in Flying and found it quite helpful.

    http://www.flyingmag.com/myth-maneuvering-speed

    The Harvard has different Va for different controls/axes, if I recall correctly. From memory rudder/yaw has quite a low Va (95 knots?), pitch, which might be standard Va around 130 knots, and roll a higher figure 160 knots?

    The article implies that Va is mainly related to vertical gust speed and pitch, although the other school of thought is that for modern certified aircraft Va is applicable to all controls individually, and you can exercise full rudder control, for example, at Va for your mass without worrying about bending your aircraft.

    The old school seems to make sense and there are different Va for different axes/flying controls.
    Last edited by SJ; 09-14-2016 at 05:09 PM.

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    Last edited by stewartb; 09-13-2016 at 09:24 AM.

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    little wing's Avatar
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    WOW! Thanks L18, haven't known that about Va. Appreciate the Flying article, all should read as I think it is common for students to be taught as described therein.

    When I have more time I plan to review the threads you posted Stewart.

    Thank you both for investing the time.

  4. #4
    CubDriver218's Avatar
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    Interesting stuff.
    Fast or slow, always low, freedom of flight soothes the soul.

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    Eddie Foy's Avatar
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    Who would have thought you could rip the verical stab off of an airliner until a ham fisted copilot at AA did it.
    "Put out my hand and touched the face of God!"

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    Eddie Foy's Avatar
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    I was flying the A300 at AA at the time of that accident.

    I attended the AA training before the crash on advanced maneuvering and the mandatory retrain after the accident.

    The pilot flying hit the wake of a plane they were following and tried to counteract the roll with the rudder.

    A characteristic of swept wing airplanes is that after they pass a certain AOA, the rudder becomes more effective at rolling the plane than the ailerons.

    He was not at that crossover point and got a bit carried away. He caused the crash doing what he thought was best. He was wrong.

    We were all retrained to emphasize this rudder phemomenom and that you could break the vertical stab off by rapidly applying full rudder one way and quickly pushing to the stop the other way.
    "Put out my hand and touched the face of God!"

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    skywagon8a's Avatar
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    I seem to recall that they found the entire vertical tail of the Air France airbus floating in the South Atlantic. That seems to be a bad habit of those machines.
    N1PA

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    Eddie Foy's Avatar
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    Quote Originally Posted by skywagon8a View Post
    I seem to recall that they found the entire vertical tail of the Air France airbus floating in the South Atlantic. That seems to be a bad habit of those machines.
    Pete that accident was totally different and had nohing to do with the vertical stab. Its not an Airbus thing.

    Faulty analogy.
    Last edited by Eddie Foy; 09-13-2016 at 05:08 PM.
    "Put out my hand and touched the face of God!"

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    skywagon8a's Avatar
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    I didn't mean to imply that the pilot over ruddered it breaking it off, only that it broke off for some reason in one big piece. Perhaps when it impacted the ocean, obviously over stressed.
    N1PA

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    Eddie Foy's Avatar
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    Quote Originally Posted by skywagon8a View Post
    I didn't mean to imply that the pilot over ruddered it breaking it off, only that it broke off for some reason in one big piece. Perhaps when it impacted the ocean, obviously over stressed.
    Second waffle from you in two days.

    The problem was not with the design of the rudder in both cases, Why bring it up?
    "Put out my hand and touched the face of God!"

  11. #11
    Eddie Foy's Avatar
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    Quote Originally Posted by skywagon8a View Post
    I seem to recall that they found the entire vertical tail of the Air France airbus floating in the South Atlantic. That seems to be a bad habit of those machines.
    What? That they float when they crash.
    "Put out my hand and touched the face of God!"

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    skywagon8a's Avatar
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    This is the vertical tail from Air France 447. Did it come off before the crash or during the crash?

    Click image for larger version. 

Name:	tail-fin_1419905i.jpg 
Views:	15 
Size:	31.1 KB 
ID:	27657

    Eddie, you are correct about the co-pilot on the AA A-300 apparently he had a history of overreacting.
    http://asndata.aviation-safety.net/r...306_N14053.pdf
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    in certain models of the Airbus the rudder does appear to be a week link. I was told that there was more to our (AA) rudder departing from the aircraft than the F/O 's action with the rudder.

    I do not see any relavence to what happened with the A300 to the discussion concerning the operation of a small aircraft like our Cubs. Also to refer to the F/O as "ham fisted" is totally unfair.
    Last edited by CuBob; 09-14-2016 at 06:07 AM.

  14. #14
    skywagon8a's Avatar
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    I heard that there had been major damage done to the fin on the crashed AA Airbus prior to initial delivery at the factory. That the fin spar had been repaired prior to delivery instead of being replaced. Somewhere I read a detailed report on this. I was led to believe that the fin failed in the region where that repair was accomplished. That is not to say that the final failure was preordained, just that there is a question.
    N1PA

  15. #15
    Eddie Foy's Avatar
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    Quote Originally Posted by CuBob View Post
    Also to refer to the F/O as "ham fisted" is totally unfair.
    He had a documented history of misuse of the rudder. Would you be happier with "ham footed?". I wish that folks would use their real names when they call someone out.

    The NTSB blamed the crash on the pilot's "unnecessary and excessive rudder" movement, which is controlled by foot pedals.
    Last edited by Eddie Foy; 09-14-2016 at 06:56 AM.
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    Perhaps C&R would be a better place for this type of discussion

  17. #17
    Eddie Foy's Avatar
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    Quote Originally Posted by CuBob View Post
    Perhaps C&R would be a better place for this type of discussion
    Hardly. That horse has been flogged to death. I dont go there.
    "Put out my hand and touched the face of God!"

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